



UNITED STATES OF AMERICA .t 















































✓ 


THE 


PROBABLE INFLUENCE 


OP 


ICEBERGS UPON DRIFT. 

BY JOHN L. HAYES. 


6 


BEAD BEFORE THE 


ASSOCIATION OF AMERICAN GEOLOGISTS AND NATURALISTS, 


MAY 4, 1843. 


7 


Published in the Boston Journal of Natural History for Jan. 1844. 






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At a time when the attention of geologists is so generally 
directed to observing the phenomena of drift, and especially 
when the agency of ice is deemed so important to explain 
these phenomena, it seems desirable that we should have more 
extended information upon the natural history of icebergs. 
To obtain the desirable information upon this subject, I have 
directed letters to various nautical gentlemen, from whom I 
was led to expect information. I visited New Bedford, the 
great centre of the American whaling business, and directed 
my inquiries to the masters of whaling ships, who frequently 
encounter icebergs in the southern latitudes. I visited Ston- 
ington, and consulted the hardy and intelligent men who have 
prosecuted the seal fishery in the Antarctic regions, and who 
have a more intimate knowledge of the south polar regions 
than any men living. Besides drawing from these sources of 
information, I have conversed with many masters of our mer¬ 
chantmen and Labrador fishermen, who often meet the ice 
upon the Banks of Newfoundland. I have also seen three or 
four individuals who were familiar with the ice in the Arctic 
Seas. The number of persons whom I have consulted is 
nearly a hundred. I have also collected such facts from the 
authentic published accounts as might bear upon the subject 
of my inquiries. 

In making my investigations, I have been scrupulously 
careful to consult only those whose general reputation would 
entitle them to entire credit, and have principally directed my 
inquiries to the masters and officers of vessels. I have been 
influenced by no attachment to a particular theory, or desire 
to collect an imposing mass of facts. I have endeavored to 
discharge my task as one would execute a judicial commis¬ 
sion to take testimony; placing down alike negative and 
positive evidence; rejecting only that which was impertinent 
or contradictory. Those who have attributed so many of the 
phenomena of drift to the action of icebergs, may be sur¬ 
prised at the small number of facts obtained from such ample 


4 


Probable influence of 


sources of information. Yet the evidence will have the 
same scientific value as if many more positive facts were 
presented. 

The present inquiry results from the attention which has 
been given, within the last three or four years, to the so called 
glacial theory. Within that period, the structure of ice, its 
mode of formation and progression in those mighty masses 
which hang upon the mountain sides at the limit of per¬ 
petual snow, its abrading and transporting influence, have 
attracted profound attention. A distinguished philosopher of 
Edinburgh, Prof. Forbes, who expresses the importance which 
has been attributed to this subject, remarks, that “ the glacial 
theory, whether it regards the present or past history of those 
mighty and resistless vehicles of transport and degradation, 
yields to no other physical speculation of the present day in 
grandeur, importance, and interest.” Since our last meeting, 
several of the most profound philosophers and geologists of 
Europe have encamped for weeks upon the glaciers of the 
Alps, to explore their various phenomena, and have filled 
the scientific journals with their acute, though, unfortunately, 
acrimonious discussions upon the glaciers. 

The proper glacial theory, as originally proposed, which 
attributes the abrading and polishing of rocks, the transpor¬ 
tation of erratic blocks, and the formation of some of the 
peculiar accumulations or ridges of gravel and bowlders which 
occur in our drift, to the agency of mountain glaciers, has 
lost the favor which it originally received. A modification 
of this theory has been suggested by Mr. Murchison, the 
President of the London Geological Society, in his late 
annual address, whose views are nearly the same, if I mistake 
not, as those advocated by geologists in our own country. 
He supposes that icefloes, and their detritus, might be set in 
motion by the elevation of the Scandinavian continent, and 
the consequent breaking up of the great glaciers on the 
northern shores of a sea which then covered all the flat re¬ 
gions of Russia; that the bottoms of these icebergs, extend¬ 
ing to a great depth, must have, every here and there, stranded 
upon the highest and most uneven points of the bottom of 


5 


Icebergs upon Drift. 

the sea, and that the lower surface of the iceberg, like the 
lower surface of a glacier, would score and grate along the 
rock. 

I may say, in short, that the effects which have been at¬ 
tributed to the agency of icebergs by the advocates of the 
aqueo-glacial theory, are, the transportation of earth and large 
fragments of rock, the abrading and furrowing of the rocks, 
the distortion and bending of strata of clay and sand, the 
formation of bowl-shaped cavities by the rotatory movement 
of the stranded berg, and the formation of accumulations, or 
ridges of bowlders and gravel, like the moraines which border 
the glaciers. We must reason from actual to ancient causes, 
and, to ascertain the soundness of these views, must study the 
phenomena of icebergs in our present seas. 

[ will now proceed to present the facts which I have 
collected. 

I. As to the mode of formation of icebergs, their original 
position, and the manner in which they have been detached. 

II. The magnitude and form of those floating at sea. 

III. The direction, rate and nature of movement, the 
limits of their transport, their grounding and dissolution. 

IV. Positive and negative testimony as to the transporta¬ 
tion of fragments of rock, bowlders, mud, and earth. 

I. The islands of ice which are seen at sea, and receive 
the name of icebergs, have been, without doubt, originally 
detached from the glaciers of the north and south polar shores. 
The term Iceberg was originally given to the glaciers of 
Spitzbergen and Greenland, and is now applied by the South 
Sea sealers and whalers to the glaciers of the South Shetlands, 
South Georgia, Sandwich Land, and Terra del Fuego. Scores- 
by, the most accurate writer upon the Arctic Seas, says that 
the greater part of the icebergs that occur in Davis’s Strait are 
merely fragments of large glaciers which exist in great num¬ 
bers on the coast forming the borders of Baffin’s Bay. These 
glaciers fill immense valleys, and extend, in some places, sev¬ 
eral miles into the sea. In others, they form a precipitous 
edge at the general line that forms the coast. 


6 


Probable influence of 

In Greenland, according to Graab, the long narrow bays or 
fiords, like broad rivers, run far up amid the lofty mountains 
or table-lands of the interior. The vast plains of the interior 
abut upon these fiords; hence the greater number are closed 
by a glacier, close to which the water has often a depth of 
several hundred fathoms. Several of the inlets are now com¬ 
pletely filled up, and at others the ice projects far out into the 
waves, forming a considerable promontory. 

1 have obtained from Mr. Fernald, of Portsmouth, a gen¬ 
tleman of great intelligence, and of remarkably accurate 
habits of observation, a statement prepared from a minute 
journal of the facts observed by him, in relation to ice, during 
a residence of fifteen months among the islands of South 
Georgia and Sandwich Land. He observes that “ the Island 
of South Georgia, lying in latitude 54° 30', is deeply in¬ 
dented with bays, some of them so deep on opposite sides as 
almost to meet in the centre. Many of the bays have large 
icebergs at their head, not yet free from the shores. During 
our stay there,” he says, “ I visited many of the icebergs. 
They were all formed in the valleys, at the head or sides of 
the bays, between the mountains, and make off into the sea. 
The snow falls to great depths on the mountains and valleys. 
The rays of the low summer sun, not reaching the snow in 
the valleys, melts it on the tops and sides alone of the moun¬ 
tains. The streams running down upon the great body of 
snow in the valleys, and congealing every successive year, 
add annually a new covering, until the whole space between 
the mountains inland, and on the side next the bay, presents 
a perpendicular and sometimes overhanging mass, several 
hundred feet high above the water, and a mile or two in 
length.” 

He further remarks, “ In our cruise we searched some of 
the islands at Sandwich Land. In some places the ice made 
from the tops of the highest hills down into the sea. In one 
place, in particular, the sea had washed in under the ice as 
far as we could see, and this huge body of ice, four or five 
hundred feet in height on its face, and a mile or two in length, 
hung, not touching the beach by four or five feet, except at 


Icebergs upon Drift. 


7 


the sides of the mountains where it formed. The face next 
the sea was nearly perpendicular.” 

Nearer the south pole, the glaciers are not seen in the 
valleys and between the mountains alone, but along the whole 
shore. Captain Benjamin Pendleton, of Stonington, who 
cruised Palmer’s Land for some hundred miles, and who, 
indeed, sent Palmer to explore the continent which has re¬ 
ceived his name, informed me that the ice rises from the 
shore, in some places, apparently 1500 feet; while, in the 
interior, the mountains rise like the Andes. The land is so 
concealed by the ice, that only a point is here and there seen. 
In the account of the Expedition of the Astrolabe, D’Urville 
says, that in passing along the newly-discovered continent of 
Adelie, they skirted, for twenty leagues, a perfectly vertical 
wall of ice, elevated 120 to 130 feet above the waves, whose 
surface was perfectly level. Here we have the source of 
some of the enormous level icebergs of which I shall hereafter 
speak. In other places, a coast was presented from 12 to 
1800 feet in height, which was completely levelled upon its 
summit by the ice and snow, having only ravines and bays 
along the shores. Captain Ross describes the glaciers on the 
coast seen by him in the 70th degree of south latitude, as pro¬ 
jecting many miles into a deep ocean, and presenting a per¬ 
pendicular face of cliffs. 

The fixed icebergs of the northern and southern polar re¬ 
gions being proper glaciers, we must expect to find them 
governed by the same laws, and exhibiting the same general 
phenomena, as the glaciers of the alpine summits which have 
been so thoroughly explored. 

Like the glacier, the fixed iceberg is formed by the yearly 
accession of the winter’s snow, which is transformed into neve 
or granular snow, or, as Mr. Emmons calls it, metamorphic 
snow, and then into glacial ice, by the absorption and con¬ 
gelation of the rain or water, which proceeds from the melting 
of the neve or snow. In the Antarctic regions, the annual 
accession must be very great. Mr. Davison, of Stonington, 
informs me that, when they first reach the South Shetlands, 
after seal, in the early part of the summer, the snow upon 


8 


Probable influence of 


the islands is nearly twenty feet deep. Even as far north as 
South Georgia, according to Mr. Fernald, the depth of snow 
from a single fall in winter is often over five feet. 

Intelligent observers, as, for instance, the commander of 
the French Exploring Expedition, have found it difficult »to 
account for the formation of the glacial ice, as no marks of 
stratification from the annual deposit were seen by him in the 
southern glaciers. But this appearance, as is shown by the 
observers of the Swiss glaciers, is replaced by a new struc- 
ture which the glacial ice assumes in the course of its forma¬ 
tion. This is a vertically-veined and ribboned structure of 
blue and white ice, resulting from an alternation of more or 
less compact bands of ice, their breadth varying from a small 
fraction of an inch to several inches. 

The imbedding of bowlders and fragments of rock is a 
well-known phenomenon of the Swiss glaciers. De Martens, 
in his memoir upon the glaciers of Spitzbergen, says that 
blocks of rock exist at the surface and in the interior of the 
glaciers or fixed icebergs of that island. Mr. Fernald ob¬ 
serves that, while at South Georgia, he visited an iceberg in 
a valley several hundred acres in extent. It was mostly cov¬ 
ered with small stones, that appeared to have been washed 
down from the tops and sides of the mountains. This ice¬ 
berg was nearly level, and about fifty feet above the surface 
of the sea. It was full of chasms, running in all directions, 
some thirty or forty feet deep. He remarked, at the time, 
that one of them was large enough to drive a cart through. 
The water was pouring down the mountain-sides, at the head 
of the iceberg, into the chasms, in streams large enough to 
turn a cotton-mill. This was in midsummer. He afterwards 
visited this glacier in winter; every chasm was filled up, and 
the whole iceberg had a new face. 

Captain William Pendleton, of Stonington, remarked to 
me, before I called his attention to the subject, that there was 
something very singular about the ice of the South Shetlands. 
This was, that there would be often seen large rocks and 
pieces of stone projecting from the cliff of ice which formed 
the shores, some of them of many tons weight. These rocks 


9 


Icebergs upon Drift. 

had often particularly attracted his attention, and he could 
not account for their being so found. Mr. Thomas Davison, 
of Stonington, also informed me that he had seen rocks of 
several tons weight in the side of a fixed iceberg, where a 
portion had fallen off. 

The glaciers of the South Shetlands and Sandwich Land 
are frequently covered with earth and sand, which appear 
to be often of a volcanic character. 

Captains William and Benjamin Pendleton, Messrs. William 
Ash, and Thomas Davison, of Stonington, have separately 
described to me a singular phenomenon, which was observed 
upon the high glaciers of the South Shetlands, at the height 
of several hundred feet above the level of the sea. In many 
places, near the immense fissures which occur in those glaciers, 
are seen piles of black earth and sand. These piles or heaps 
of earth appeared precisely as if they had been carted and 
dropped in various places along the ice. Immediately below 
the earth, the hard blue ice could be seen, in the fissures, ex¬ 
tending down hundreds of feet. This phenomenon, I think, 
must be peculiar to volcanic regions like the Shetlands. It 
would be difficult to account for the peculiar form and posi¬ 
tion of these piles of sand without the supposition of volcanic 
action. 

The low glaciers would seem to be more thoroughly cov¬ 
ered. Captain Benjamin Pendleton informed me that, in 
1821, he lost a seaman at the South Shetlands, and, with 
a gang of twelve men, went ashore upon one of the islands 
to bury him in the earth. They dug in a great many places 
through the blue sand and earth ; but, after digging six or 
eight inches, invariably came to the blue solid ice. They cut 
a hole in the ice, into which they placed the body, covering 
it with sand and ice, placing up a board, alas! the sailor’s 
only monument, to mark the spot. In 1832, eleven years 
after, Captain Barnum dug the body from the ice, and found 
the body and clothes appearing as if they had been just de¬ 
posited. 

Mr. Fernald visited a volcanic island in Sandwich Land, 

2 


10 


Probable influence of 


whose centre was occupied by a very high peak covered with 
ice. The shores were covered with scoriae and volcanic 
ashes, which appeared as if they had been recently deposited ; 
for in some places smoke or gas was seen escaping. They 
dug into the scoriae and sand to the depth of a foot or 
more, to find the source of the smoke, and found that the 
scoriae and sand were but a superficial covering for the hard 
ice, which extended from the central peak to the sea. 

If we review the facts now presented, we have exhibited 
the phenomena of fixed icebergs or glaciers, strewed with 
stones transported from the mountains, and covered with a 
new deposit of ice and snow; large blocks of stone, in the 
perpendicular wall of the iceberg, overhanging the sea; piles 
of sand on the high glaciers; sand and volcanic scoriae cov¬ 
ering the low glaciers upon the borders of the sea; and a 
body preserved for years from decay in the solid ice, and 
which might there remain thousands of years, like the elephant 
of Siberia. We have only to conceive of the increase of 
the low glaciers by the causes already indicated, and of the 
advance of all the ice which contains these extraneous mate¬ 
rials into the deep seas which wash the polar coasts, of por¬ 
tions being detached, and floating into northern seas, to have 
in action, in our own day, the power which is supposed to 
have transported the materials of the drift from the ancient 
mountain-sides. 

The supposition above made, that the glaciers, situated as 
those above described, might, in time, reach the sea, and be 
floated from the shore, will not appear improbable, when we 
consider the manner in which the glaciers advance, and the 
separation of the iceberg from the shore. Upon this difficult 
subject, the researches of Charpentier, Agassiz, Forbes, and 
others, on the glaciers of the Alps, have thrown much light. 
The glaciers of the Alps and Spitzbergen are filled with innu¬ 
merable fissures, produced, as Agassiz conjectures, by the 
expansion of compressed bubbles of air within the ice. These 
fissures are generally parallel with the front face of the glacier ; 
larger fissures or crevices are produced during summer. The 


Icebergs upon Drift. 


11 


innumerable fissures render the glaciers porous and permeable 
to water. The dilatation of the water freezing in the crev¬ 
ices, constantly tends to the enlargement of the glacier, which 
must advance in the direction where there is the least resist¬ 
ance. Although, in some cases, the weight will add to its 
progression, it is owing to this expansion, principally, that, at 
certain seasons, the glaciers constantly tend to advance. It 
would seem that fissures, precisely analogous to those of the 
Alps and Spitzbergen, are seen on the glaciers or fixed ice¬ 
bergs of the Antarctic regions. 

Captains Pendleton, Messrs. Ash and Davison, and Captain 
Frederick G. Low, of Gloucester, all speak of the enormous 
fissures or chasms which are found on the surface of the 
glaciers, at the height of many hundred feet above the sea. 
These fissures are described as running parallel with the 
shore, and are often several miles in length. The observers 
have particularly noted their length and width, from being 
often obliged to walk along them for a great distance before 
finding a place narrow enough to be crossed in safety. Cap¬ 
tain Barnham judged that they were sometimes over five 
hundred feet deep, as he has been unable to see the bottom 
when looking down. Captain Low informs me, by letter, 
that he measured the depth of one eighteen inches wide, into 
which he fell when the ice was covered with snow, although 
he saved himself by extending his arms, and found it seventy- 
five feet deep. The description given by all, of the extreme 
beauty of the azure light reflected from the walls of the 
fissures, strikingly reminds one of the accounts, given by 
Agassiz and others, of the same appearance in the fissures of 
the Swiss glaciers, a peculiarity of color which Agassiz says 
is witnessed only in the mountain waters. 

Prof. Forbes says that these singular vaults on the Alps 
•have all the grotesque varieties of outline which are so much 
admired in calcareous caverns, but which here show to far 
greater advantage, in consequence of their exquisite transpa¬ 
rency and lustre, and from being illuminated, instead of by a 


12 


Probable influence of 


few candles, by the magical light of a tender green, which 
issues from the very walls of the crystal chambers. 

Men and dogs have often been lost in these fissures while 
crossing the glaciers, when they were covered with snow. 
The sealers use the precaution of passing a small rope around 
their waists, to be held by their companions when crossing 
the glaciers, which are covered with snow. 

1 may be pardoned for relating an anecdote of a remarka¬ 
ble escape, which was told me by several individuals who 
knew the fact. A young man from Stonington, who visited 
the South Shetlands on a sealing voyage, was anxious to ex¬ 
plore one of the glaciers; as he could not induce his com¬ 
rades to accompany him, he started alone. While walking 
on the surface of the glacier, which was then covered with 
snow, he fell into a fissure, to the depth, as was supposed, of 
over a hundred feet. He was so much bruised and injured 
by the fall, that he remained senseless, it was supposed, some 
hours. Upon reviving, he found himself wedged between 
the walls of the narrowing chasm. His first feeling was re¬ 
gret that he had not been instantly killed, as there appeared 
no mode of escape. But, as he thought of dying in such a 
manner that his friends would never know of the place or 
manner of his death, he determined to make an effort to save 
his life. Taking his jacknife, he began to cut steps for his 
feet in one side of the wall, while he pushed himself up with 
his back. He continued cutting until his fingers were com¬ 
pletely lacerated by hard, sharp ice, and until the chasm be¬ 
came so wide that he could just reach the ice with his knife. 
However, he at length reached the surface, and was found by 
his comrades crawling along the glacier, twenty-four hours 
after he had fallen. Although he thus wonderfully escaped 
with his life, he was so lacerated and bruised that he was unfit 
for labor for several months. As my informant said, no one 
but a man of remarkable spirit and strength would have had 
the energy to save himself under such circumstances. 

The same expansive power existing in the glaciers of the 


Icebergs upon Drift. 


13 


polar regions as in those of the Alps, they must be constantly 
advancing into the sea, as the glaciers of the Alps do along 
the valleys. It is well known that, on the Alps, these pro¬ 
longations of the winter-world above are protruded into the 
midst of warm and pine-clad slopes and green sward, and 
sometimes reach even the borders of cultivation. As Prof. 
Forbes says, the very huts of the peasantry are sometimes 
invaded by this moving ice; and many persons now living 
have seen the full ears of corn touching the glacier, or gath¬ 
ered ripe cherries from the tree with one foot standing on 
the ice. 

The deep seas, which are always found near such moun¬ 
tainous coasts, readily float away those masses which become 
detached. No one whom I have particularly examined has 
ever witnessed the actual separation of those vast islands 
which are found floating, and of which 1 shall hereafter speak. 
But, from the accounts of all those who have visited the 
southern glaciers, immense masses are constantly falling from 
the ice-cliffs, which are floated away by the sea. Captain Benja¬ 
min Pendleton informs me that he has seen the ice fall from a 
cliff for the length of half a mile. The noise made by the 
bursting of the glacier and fall of ice is compared to thunder. 
When the sealers first visited the South Shetlands, they sup¬ 
posed the noise made by the bursting of the iceberg was oc¬ 
casioned by shocks of an earthquake. The harbors and bays 
in which the sealers lie are often filled in this manner by the 
fall of ice. .Mr. Curtis, of Portsmouth, who was with Mr. 
Fernald in South Georgia, stated to me, that on one occasion 
they put into Merry’s Bay, on South Georgia. The sea and 
the harbor, when they put in, was entirely free from ice. The 
next morning, the bay was so filled with ice that fell during 
the night that they could not get out to sea. They went upon 
the hills at the head of the bay, and, although the weather 
was clear, could see ice as far as the eye could reach. 

It is a fact, which should be remembered in connection 
with the object of our inquiries, that the greater portion of 
the ice falling from the glacier, consists of comparatively small 


14 


Probable influence of 


masses ; a large portion of the ice would be dissolved or 
broken up before being transported to a great distance from 
its source. For, though smaller masses would be tossed about 
by the winds and waves, and might be easily dashed to pieces 
on the shore, a large portion of the foreign materials of the 
glacier, being detached with the smaller masses of ice, would 
be dropped within a comparatively short distance from the 
glacier. 

An interesting phenomenon, connected with the fall of ice 
in the glacial seas, is the formation of enormous waves by the 
sudden displacement of large masses of water. Captain Low 
informs me, in his letter, that the ice in the harbor where he 
lay, was from three hundred to a thousand feet high ; and 
that, whenever there was a heavy fall of ice, it made so much 
swell that the ship would roll three or four streaks. Mr. 
Fernald says that, in one of the bays of South Georgia, where 
there was a large fixed iceberg or glacier, which he judged to 
be four hundred feet high, they landed from the boat to search 
the beaches for seal. The boat was hauled up on the beach, 
her stern just touching the water, when a large piece fell from 
the iceberg into the bay, and made such a sea as to throw the 
boat sixteen feet upon the beach. The bay was at this place 
a mile wide. This statement is corroborated by two other 
individuals of the same party, who well remember the fact. 
Mr. Darwin speaks of a great wave produced by the fall of 
ice in Terra del Fuego, which he witnessed, and justly re¬ 
marks that the waves formed by the fall of ice must be a 
powerful agent in rounding and sweeping together large frag¬ 
ments of rocks, and likewise in wearing away projecting por¬ 
tions. They must also be powerful agents in lifting up and 
bearing away large icebergs already loosened, in breaking to 
pieces the smaller bergs, in purging the larger icebergs from 
the extraneous matters with which they may be loaded, and 
in loosening and detaching fragments of rock — effects which 
we shall hereafter see must often have been produced on ice, 
at no great distance from their place of departure. 


15 


Icebergs upon Drift. 

II. As the aqueo-glacial theory of drift supposes the ice¬ 
bergs of the ancient seas to have been agents of enormous 
power, we may judge of the probability of these conjectures 
by inquiring as to the magnitude and form of those found 
floating in our present oceans. 

Those which come from Baffin’s Bay, although often of 
great height, appear to be of less extent than those seen south 
of the equator. Captain Crocker, of New Bedford, measured, 
with his sextant, one which was aground upon the Banks of 
Newfoundland, and found it to be two hundred and forty-four 
feet in height, and half a mile in length. Parry counted from 
his deck, at one time, no less than one hundred and three ice¬ 
bergs, some of them from one to two hundred feet in height. 
Captain Ross, in Baffin’s Bay, saw seven hundred in sight at one 
time, and several aground together, in 250 fathom, 1500 feet. 
Those found in the Southern Ocean are of vast dimensions. 
Several have spoken to me of icebergs which they judged to be 
three or four miles long. Captain William Beck, of New 
York State, informed me that, in 1835, in latitude 46°, he 
saw an iceberg which must have been from five to ten miles 
long. His own impression, and that of the master of the 
ship, was that it was no less than ten miles in length; when 
they first saw it, they supposed it to be land. They were an 
hour and forty minutes in sailing by it with a good wind. 
Mr. Fernald and Mr. Curtis saw one near South Georgia 
which they judged to be from ten to fifteen miles in length, 
as they were several hours in rowing by it in a six-oared boat. 

The estimates, made without actual admeasurement, cannot 
be much relied upon, although I am inclined to think those 
given by my informants have been rather within, than beyond 
the truth. It will be interesting to refer to admeasurements 
carefully made by the officers of the French Exploring Expe¬ 
dition. I found that ten icebergs, whose dimensions were 
given in one of the charts accompanying the account of the 
Expedition of the Astrolabe, were between 90 and 150 feet 
in height. Four were between 180 and 225 feet in height. 
Sixteen, which, with two exceptions, were over 100 feet 


16 


Probable influence of 


high, were from about 4000 to 6500 feet in breadth. Cap¬ 
tain D’Urville remarks that, in going towards the west, they 
had already seen some icebergs of fine dimensions, attaining 
from about two miles and a half to five miles in length, 
not to speak of their breadth. But, on the 20th of Feb¬ 
ruary, they passed one which, having been accurately 
measured, they found to be a compact mass, 11,000 toises, 
over 13 miles, in length, and 100 feet high, with walls per¬ 
fectly vertical. When we remember that the submerged 
portions of these icebergs must be from six to eight times 
more considerable than the portion which is visible, — for 
the experiments upon the weight of ice give about these 
proportions, — we may be truly astounded at their magnitude. 
We may see in these floating ice-rocks, when fairly set in 
motion, an agency of almost resistless mechanical power. 
The ploughing up, or levelling and pushing along the loose 
materials composing the shoals, which their lower portions 
might touch, the piling up of sand and pebbles along their 
sides and extremities, and the grating and binding of rocks 
and beds of clay, are effects which we may readily conceive 
to have been produced by them. 

We cannot omit to allude to the various and picturesque 
forms which icebergs exhibit, although, perhaps, no connec¬ 
tion may be traced between their forms and the mechanical 
effects attributed to them. Every variety of form may be 
seen, from the huddled, peaked, and furrowed surface, to a 
uniform plain. To one observer, the marvellous spectacle 
which their fantastic forms present, recalls the palaces of 
crystal and diamonds, so common in fairy tales; another 
beholds merely an island, with level summit and vertical 
walls, resembling cliffs of chalk, in which he seeks in vain for 
the picturesque beauty which he has heard described. The 
remarkable resemblances, which have been noticed in these 
ice-islands, cannot exist merely in imagination ; for the ac¬ 
count given me by a rough, old whaler, who could see Amster¬ 
dam and Rotterdam, with their steeples, balconies, and por¬ 
ticoes, in the icebergs which beset his vessel, is repeated by 


17 


Icebergs upon Drift. 

the polished French navigator, who says that, as the sun 
shone upon the ice of the Antarctic, it appeared like an im¬ 
mense city, with its palaces, its domes, and its towers. 

III. I will now proceed to examine the facts which will 
serve to explain the mechanical power of moving icebergs, 
and consider the nature and rate of their movement, their 
overturning and stranding. 

All the observers whom I have examined, speak, without 
exception, of the extreme slowness and steadiness of the 
motion of large floating bergs. Nearly all say that they ap¬ 
pear to be wholly unmoved by the r winds or waves, although 
one or two say that thfey appear to be very slowly moved by 
the wind. Scoresby says that, in the strongest gales, they are 
not perceptibly moved. Mr. Fernald remarks that the motion 
of large icebergs is imperceptible. “ I have seen them,” he 
says, “ in a heavy gale, with a tremendous sea running; they 
appeared as steady and motionless as the earth. The sea 
dashes on their windward side as upon a fixed rock, while 
under their lee a vessel may lie in perfect safety.” Mr. Cur¬ 
tis remembers lying to in a small schooner, under a large 
ice-island, during a tremendous gale; yet the little craft lay 
perfectly safe, and made good weather. So great a portion 
of the large icebergs being below the surface, their motion 
must be principally influenced by the under currents, which 
have a regular and steady flow. 

The irregularity and unsteadiness in the movements of ice¬ 
bergs has been considered an important objection to the the¬ 
ory which ascribes the ancient diluvial scratches and furrows 
to the scoring and grating of the iceberg along the rock. If 
the facts and testimony which I have presented can be relied 
upon, they show, in the icebergs of the present seas, precisely 
that regularity of movement which was required to produce 
the effects ascribed to the icebergs of the ancient seas. 

I have carefully examined all those who have seen icebergs, 
as to the rotatory motion which has been attributed to them. 
No one of those whom I have examined ever saw any such 
3 


18 Probable influence of 

motion, with, perhaps, the exception of Captain Barnum, who 
says that he has seen an iceberg move very slowly on its 
vertical axis. Captain William Howland, who was engaged 
in the seal fishery in the northern seas, and whose employ¬ 
ment led him to land often on the icebergs to procure seals, 
says that it was impossible that such a motion should have 
occurred without his observing it. It is a well-known fact, 
that the Greenland whalers and sealers move their vessels to 
the floating icebergs, to protect themselves from the drift ice. 
According to this evidence, some other cause must be sought 
for the formation of the bowl-shaped cavities which occur in 
the drift, than the rotatory or semi-rotatory movement of ice¬ 
bergs. 

The only remarkable movement which has been observed 
in floating icebergs is that occasioned by their overturn. 
This phenomenon has been noticed by all observers. The 
falling of portions of the mass, which is called the calving of 
the iceberg, or the wasting of the lower portions by warm 
water, destroys the equilibrium of the berg, and causes it 
either to overturn entirely, or so far as to bring a new surface 
to view. Although, from the descriptions which are given, 
the overturn of a huge iceberg in a calm sea, while the sun 
is shining upon its glittering peaks, with all the circumstances 
of the crushing of the fractured ice, the foaming and rolling 
of the disturbed water, the sudden change in the form and 
outline of the mighty mass, must form a scene of surpassing 
grandeur, the only effect which has interest in our inquiries 
is the production of enormous waves, equalling or surpassing 
those produced by the fall of ice, which are said to be so 
heavy as to endanger boats at the distance of several miles, 
and, in a perfect calm, to have dashed over the bows of a 
vessel of forty tons, at a distance of five miles. By this 
agency, Scoresby says, fields of ice are often broken up; and 
by the same agency the stranded bergs might be lifted up, 
and urged along the bottom upon which they are grounded. 

Icebergs are often seen aground in great depths of water. 
I have already mentioned those seen aground by Ross in 


19 


Icebergs upon Drift. 

1500 feet of water. The large proportion of the mass which 
is below the water, must cause them to be very easily and fre¬ 
quently stranded. None of those whom I have examined 
have ever witnessed any movement in the stranded bergs, 
with the exception of Captain Low, who, in his letter, remarks 
that icebergs, when aground, have the same laboring move¬ 
ment that a ship in shore would have, with a heavy cargo 
and a heavy swell. It is difficult, however, to conceive how 
a large iceberg, a great proportion of whose mass is below 
the influence of the swell, could have a movement analogous 
to that of a ship which is lifted by every wave. It would 
seem, therefore, that the formation of hollows in the drift 
cannot be explained by supposing the grinding and settling 
down of the stranded berg into the loose materials. 

That an immense lateral force must often be exerted by the 
pressure of the iceberg upon the shore or shoals against which 
they may be driven, is shown by a fact stated by Dr. Rich¬ 
ardson— that the icebergs in the Arctic seas are driven with 
such force against the shore, that they push before them, to 
the height of several feet, every pebble or bowlder which lies 
upon the bottom. 

The length of time during which icebergs remain aground 
may have some bearing upon the subject of this inquiry. 
Captain Simpson, of New Bedford, saw an iceberg, half a 
mile in length, aground at the mouth of the River La Plata, 
in the winter, where it was wasting away during two months. 
Captain Benjamin Pendleton saw one aground in 80 fathoms, 
near the South Shetlands. Captain Barnum saw one aground 
in McFarlane’s Strait, three or four miles in length. He saw 
it for two years, and several of his crew remembered it as one 
which was seen by Captain Pendleton’s party eleven years 
before. Captain Matthew Luce, of New Bedford, saw one 
100 feet high, aground in 48 fathoms, on the Banks of New¬ 
foundland. The fishermen had fished around it for thirty 
days. Barriers of this magnitude, remaining for so long a 
period, must exert a strong influence upon the distribution and 
deposit of loose materials. Icebergs stranded where the 


20 


Probable influence of 


detritus, borne down by rivers or moved by currents, are 
deposited, as the instances of this aground at the mouth of 
the La Plata or the Banks of Newfoundland, would be, in 
time, surrounded by the loose materials; the dissolution or 
foundering of the berg would present hollows like those seen 
in the drift; or the iceberg might protect the bank upon 
which it was aground, and prevent it from being washed 
away, while the materials all around might be carried away. 
The dissolution of the berg would leave a hill. 

In connection with the subject of drift, it is interesting to 
observe the direction in which the present icebergs are carried 
from their source, and the northern and southern limits of 
their transport. Their general course, as is well known, is 
from the polar towards the equatorial seas, transported as 
they are by the currents which set from the poles towards 
the equator. If the northerly and southerly direction of these 
polar currents is due to the excess of evaporation in the 
warmer seas, and a flow of water from the colder oceans to 
supply the loss, a theory which has been proposed by the 
French philosophers, although I hardly dare to suggest any 
theory, similar currents must have prevailed in the ancient 
frozen seas, so that the ancient currents must have corres¬ 
ponded with the general course of the drift. 

The facts collected, as to the northern and southern limits 
of the transport of ice, are as follows: Captain Crocker, of 
New Bedford, who has crossed the ocean in command of a 
packet ship one hundred and sixty-four times, says that he 
never saw icebergs south of the 40th degree of latitude, and his 
impression is that all seen south of the 46th degree are small. 
Captain Luce, of New Bedford, has seen them in 41° north 
latitude. They have been seen near the Azores, in latitude 
42°. Captain Lane, of Portsmouth, informed me that, in 
the year in which the President was lost, in going to Mar¬ 
seilles, his ship came near striking an iceberg in about .41°, 
and as far east as the 19th degree of longitude. There is no 
evidence of their having been seen in the northern hemisphere, 
south of latitude 40°. In southern latitudes, icebergs have 


21 


Icebergs upon Drift. 

been seen at different points off the Cape of Good Hope, 
between latitudes 36° and 39°. One seen in those latitudes 
was two miles in circumference, and 150 feet high. They 
have been seen at the mouth of the Rio de la Plata, in lati¬ 
tude 36°. Captain Simpson informs me that he has several 
times heard of them off Cape Antonio near the same lat¬ 
itude. 

These immense masses cannot owe their destruction alone 
to the melting of their surface by the sun or the heat of the 
water. Did their dissolution depend alone upon this cause, 
they might often be transported within the tropics. They 
seem to contain within themselves a principle of destruction, 
after they have been subjected to air or water of a certain 
degree of temperature. Captain William Howland informed 
me that the icebergs in northern seas, among which he cruised 
in pursuit of seals, would often founder, as he expressed it, 
during the summer weather. This foundering was produced 
by the bursting of the large bergs with a tremendous report, 
louder than that of a cannon. After the explosion, not a 
piece of ice larger than a hogshead would be visible. 

Mr. Ichabod Goodwin, a merchant of high standing in 
Portsmouth, who was formerly a shipmaster, informed me 
that he was crossing the Atlantic in the ship Marion, in the 
month of May, 1827, when, in latitude 41° 30', and in longi¬ 
tude 50°, they passed within a quarter of a mile of an ice¬ 
berg which they judged to be about sixty feet high, and over 
a hundred feet in length. While all hands were below, they 
heard a report like the discharge of a cannon, and, upon 
rushing on deck, found that the iceberg had exploded, and 
had gone completely to pieces. The sea where it just before 
lay was in considerable agitation. Upon looking with a glass, 
an hour after, not a particle of ice could be seen. Captain 
Lake, of Portsmouth, has witnessed the same phenomenon 
off Labrador. 

This explosion of the iceberg may be attributed to the 
same cause to which Agassiz attributes the Assuring of the 
glaciers, namely, the expansion of the air, compressed at the 


22 


Probable influence of 


time of the freezing and formation of the berg. The com¬ 
paratively small number of icebergs seen in lower latitudes, 
favor the conjecture that this must be a common mode of 
destruction. Without some such agency, our oceans would 
be completely obstructed with floating ice. 

The fixed limits which appear to be thus assigned to the 
transport of icebergs is an interesting fact, and peculiarly so 
in connection with the aqueo-glacial theories of drift, if the 
statement made by Humboldt, and repeated by Darwin, is 
correct, that no angular fragments are found in the vast inter- 
tropical plains of South America, and that, within the south¬ 
ern and northern hemispheres, no fragments coming from 
polar regions or mountain groups arrive within any consider¬ 
able distance of the limit of the tropics. 

IV. The most important view in which icebergs are to be 
regarded is with respect to their influence in the transportation 
of bowlders and angular fragments of rock and earth. Most 
geologists unite in supposing that icebergs were important 
agents in lifting and distributing the enormous bowlders and 
erratic blocks which are found in the drift, at a distance from 
their parent rocks. I shall give all the positive and negative 
evidence which I have been able to collect upon this point. 

Captain William Howland, who was in the constant habit 
of landing upon the icebergs in the northern seas, observes 
that he has often seen bowlders and fragments of rock from 
four to six feet in diameter, although not more than one in a 
hundred would have any foreign matters on it. Captain 
Sampson, of New Bedford, informed me that he once saw, 
on the sloping side of a large iceberg, upon the Banks of 
Newfoundland, a large quantity of earth. It appeared to be 
about a foot in thickness; near the water it had been washed 
away by the waves. The space thus covered seemed to him 
to be about fifty feet in width, and an eighth of a mile- in 
length. 

Captain Barnum, of Stonington, informed me that he saw, in 
latitude 55° south five large islands, whose surface was black 


Icebergs upon Drift . 


23 


with an admixture of earth and stones. Being struck with 
the appearance of the icebergs, he landed upon one. Many 
of the stones were a foot in diameter. They had sunk in the 
ice, and small pools of water had formed around them. 

It would seem that the occurrence of foreign materials 
upon the icebergs is to be observed principally near their 
source. Captain Benjamin Pendleton remarked that, upon a 
large number of the icebergs in the extreme southern lati¬ 
tudes, and especially near the South Shetlands, bowlders 
and fragments of rock of various sizes could be seen. He 
compared their magnitude to the boxes and bales of goods 
lying in a country store. It was as common, he said, to see 
rocks and bowlders in the icebergs at the South Shetlands as 
to see them at Stonington Point. Those seen at a distance 
from the Shetlands, near Cape Horn, for instance, rarely if 
ever contained them. 

Mr. Low says, in his letter, that he has seen large rocks 
and earth attached to icebergs, but saw them near the shore. 
He never saw earth or rocks on floating icebergs far from the 
shore. 

Dr. Gilchrist, of the navy, who was one of the surgeons 
of the Exploring Expedition, informed me that they saw no 
bowlders or fragments of rocks upon icebergs until near the 
great barrier of ice, and in close proximity with the land, at 
which time, as is well known from Mr. Wilkes’s synopsis, 
they met with icebergs covered with mud and rock. 

These facts are entitled to observation, in connection with 
the fact stated by our geologists, that the great mass of the 
drift will be found within fifteen or twenty miles from its 
original place. 

Enormous blocks, however, are sometimes carried to a con¬ 
siderable distance from their original position. 

Captain William Beck, formerly of Stonington, informed 
me that, in latitude 63° south, and about one hundred miles 
from the South Shetlands, he saw an immense mass of round 
rock attached to a floating iceberg. The diameter of the 
rock he judged to be at least twenty feet. It appeared to him 


24 


Probable influence of 


of the size of a small house. The fact was so curious that 
he noted it in his journal. 

Fewer facts of this kind are mentioned in the narratives of 
voyagers than might be supposed from the great transporting 
agency which geologists have ascribed to floating icebergs. 

All the recorded facts of importance can be briefly pre¬ 
sented. 

The most striking is that mentioned by Scoresby, who 
speaks of five hundred icebergs, which he saw in the 70th 
degree north latitude. Many of them contained strata of 
earth and stones, and were loaded with beds of rock of great 
thickness, of which the weight was conjectured to be from 
fifty to a hundred thousand tons. This, it will be remem¬ 
bered, was so far north as to be, probably, at no great distance 
from the source of the iceberg. 

Weddel says that, when in latitude 61°, longitude 31, with 
islands of ice his constant companions, he saw an island which 
he supposed to be rock, and fully expected to find terra firma 
in a short distance. It was not until passing within 300 
yards, that they could satisfy themselves that it was not land ; 
the north side was so thickly incorporated with black earth, 
that hardly any one would have hesitated to pronounce it 
land. 

Mr. Bynoe, the surgeon of the Beagle, informed Mr. Dar¬ 
win that, more than twenty miles from the head of Sir G. 
Eyer’s Sound, they landed upon one of many floating masses 
of ice, which were only two or three feet above the surface. 
In the central part of the surface was a piece of granite, of 
an angular form, partly imbedded. The ice had melted so as 
to make a shallow pool of water around it. Mr. Sorrel, boat¬ 
swain of the Beagle, said that he had seen, in the seas 
around South Georgia, small icebergs, with mud and gravel 
upon them, floating from the shore. Mr. Sorrel also saw, 
to the eastward of the South Shetlands, an iceberg with a 
considerable block of stone upon it. 

Captain Hunter informed Mr. Darwin that he had seen 
numerous islands of ice in the neighborhood of South Georgia, 


Icebergs upon Drift. 


25 


many half black, apparently, with earth from the land to 
which they had adhered, or with mud from the bottom on 
which they had formed. 

Dr. Mertens, in his memoir upon the glaciers of Spitzber- 
gen, said that his colleague, Mr. E. Hobart, had seen floating 
ice in crossing Bell Sound, stained at the surface with earth, 
which, for the moment, was taken for islands. 

The negative testimony upon this subject will, to many, 
appear remarkable; for, of more than sixty persons whom I 
have examined, only seven remember to have seen foreign 
materials upon the iceberg. Captain Crocker, who, as I have 
before remarked, has crossed the Atlantic one hundred and 
sixty-four times, and who says that he has seen thousands of 
icebergs, never remembers to have witnessed any such appear¬ 
ance. Captain Luce, who had seen hundreds of icebergs, 
never saw any stones or earth upon them. Mr. Fernald, a re¬ 
markably accurate observer, although he says that he has seen 
hundreds of icebergs between Georgia and Sandwich Land, 
never saw stones or earth on any of them afloat. The com¬ 
mander of the French Exploring Expedition makes no mention 
of his having seen extraneous matters on the numerous islands 
seen by him, although he had been particularly instructed to 
notice such phenomena. Dr. Mertens says that, in the voy¬ 
ages of the Recherche, in the Spitzbergen seas, he never saw 
blocks transported by ice. Captain Biscoe, who had extended 
his researches in the Antarctic, says, in a letter to Mr. Darwin, 
that he had never observed, in a single instance, mud or 
fragments of stone on the numerous icebergs encountered by 
him in his voyage. The evidence upon this subject has con¬ 
vinced me that islands of ice, floating at a distance from their 
source, are remarkably free from all impurities. 

It must be remembered that the evidence upon this subject 
is negative, and not entitled to the same weight as positive 
testimony. The voyagers are so much occupied with the 
perils of navigation among the ice as to be inattentive to 
phenomena which would be observed by scientific men. 
Again, where mud or stones were attached to the bottom of 
4 


25 


Probable influence of 


icebergs at the time of their separation from the glacier or 
land, especially the level bergs, which are not liable to be 
overturned, the materials attached would never become ex¬ 
posed, while they would soon be loosened by the action of 
the water. Another consideration is to be observed. It 
cannot be questioned that the foreign materials are more 
abundant upon the icebergs near their source. Around the 
smaller stones and sand the ice is melted, so that they would 
be easily detached. Around the larger blocks, from the state¬ 
ments of Captain Pendleton, and the observations of Agassiz, 
the ice is melted, so that the large blocks project upon the ice ; 
they might thus be easily detached by contact w r ith other ice¬ 
bergs, the overturning of the iceberg, or the washing of waves 
produced by the fall or overturn of neighboring masses of ice. 

I am so fully aware of the danger which exists of forming 
altogether too broad conclusions as to past phenomena, from 
the limited examination of actual causes, that I hesitate to 
present any more general inferences from the facts now ex¬ 
hibited than such as have been already hinted at. But, as 
there seems to exist a right to demand of every collector or 
observer of facts the conclusions which he has been led to 
form from their examination, I will briefly present the infer¬ 
ences which may be drawn from the facts which I have ex¬ 
hibited as to the mechanical and transporting agency of ice 
in the ancient seas. 

1. The steadiness in the movement of the icebergs of our 
present seas, in the direction and under the influence of the 
great under currents, and the southerly course of these under 
currents in our northern hemispheres, from causes which must 
have prevailed, as well in the ancient as in our present seas, 
favor the theory that icebergs, with gravers of rock in their 
lower portions, or pressing the sand and gravel, by their im¬ 
mense weight, along the surface of the rocks, in the bottoms 
of the ancient oceans, might have scored and grated along 
the rocks, grinding off their salient points, and leaving the 
surfaces smoothed and striated in the fixed southerly direction 
in which now they occur. 


Icebergs upon Drift. 


27 


The objections that the surfaces of the rocks must have 
been often protected from the action of the moving icebergs 
by intervening mud and sand, and that the lower portions of 
icebergs could not correspond with the uneven surfaces of the 
rocks, and leave the traces of their progress alike on the 
mountain-sides and in the valleys, cannot be met by any facts 
above presented, as to the form and nature of movement of 
icebergs. We may, therefore, conclude that they have not 
been the sole instruments in furrowing and grooving the 
rocks beneath the drift. 

2. The immense magnitude of the icebergs in our present 
seas, and the evidence of their present mechanical power, 
when moved by strong currents, warrant the conclusion 
that they must have exerted a powerful influence in pushing 
and crowding along the sand and gravel which formed the 
bottoms of the ancient seas, and in thus forming accumula¬ 
tions somewhat analogous to the moraines of the glaciers. 

3. The length of time during which large icebergs may 
remain aground, even when swept by rapid currents, which 
currents might surround them with sand and mud, or sweep 
away the loose materials, leaving hills or banks upon spots 
protected by the stranded icebergs, favor the idea that this 
agency had an influence in giving the present form to our 
drift. 

4. The formation of glaciers or fixed icebergs, upon the 
present coasts, under such circumstances that fragments of 
rock, and detritus from the land upon which they form, be¬ 
come attached to them, the constant advance and separation 
of the glaciers from the land, and their floating into the sea 
as icebergs, with their loads of earth and rocks, lead to the 
conclusion that icebergs, breaking off from the shores of 
ancient seas, were important agents in the transportation of 
rocks and earth from their parent beds. The existence of 
immense fragments of rock, in situations where they could 
not have been carried by water alone, as on the sides of hills, 
with valleys intervening between them and their parent beds, 


28 Probable influence of Icebergs upon Drift. 

but where they might have been left by stranded icebergs, 
favors this conclusion. 

5. The fact that a large part of the fragments detached 
from glaciers are of small size, and that these small fragments 
of icebergs or glaciers are dissolved and broken to pieces, at 
no great distance from the parent glacier, together with the 
fact that fragments of rock, although often seen near the 
source, are rarely seen at a distance, lead to the inference, 
that the same causes limited the transportation of the bowl¬ 
ders and larger fragments of the drift, to within the compara¬ 
tively small distance from the parent rocks at which they now 
occur. 








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